The Pelicans were able to complete the deal once they decided to guarantee the $12.5 million team option on Mirotic's contract next season, which allowed the Bulls to complete the trade without Mirotic's permission, league sources said.
The Pelicans had to attach a first-round pick to unload the salary of Asik, who is owed $10.5 million this season, $11.2 million in 2018-19 and $3 million in guaranteed money in 2019-20. The Pelicans' first-round pick on its way to the Bulls is a protected top-5 selection in 2018; top-8 in 2019; top-10 in 2020; and, top-9 in 2021, league sources said.
If the first-round pick hasn't conveyed to the Bulls in 2021, it becomes a second-round pick in 2022 and 2023, sources said.
Bulls executive VP John Paxson said he was pleased with what the Bulls received in return for Mirotic and was confident this was the best deal that presented itself.
"Niko's representatives were consistent over the last several months that they wanted him moved," Paxson said during a Thursday conference call. "And they never backed off that stance one bit. I'm sure that given everything that we'd heard from them through this entire process that he just wanted to be elsewhere. This satisfies what he wanted. More than that, it satisfies what we wanted to get out of it in moving him. Again, it fits our timeline, it fits the direction we're going."
The Bulls will waive Allen but plan to keep Nelson, league sources said.
The Bulls will also send a 2018 second-round pick -- acquired via New Orleans in a trade for Quincy Pondexter -- and will have the right to swap second-round picks with the Pelicans in the 2021 draft, league sources said.
The Bulls waived Pondexter to create the roster space to complete the trade.
Mirotic signed a two-year deal with the Bulls in August. He has thrived with the Bulls, averaging 16.8 points and 6.4 rebounds since missing the first 23 games of the season after a scuffle in practice with Bobby Portis left Mirotic with facial fractures and a concussion.
ESPN's Nick Friedell contributed to this report.